The present invention relates to bearings, and more particularly to bushings for high-pressure applications.
Plain bearings or bushings are well known and include a generally annular body with an inner circumferential surface for supporting a sliding and/or rotational movement of a cylindrical body, such as a shaft or piston, along a central axis. These bushings are typically installed within an annular groove or gland that retains the body with respect to the axis. In certain applications, the bushing can be installed within a gland by sliding the body axially into an open end of the gland, and then “closing” the gland with an adjacent structural member (e.g., retainer ring in a bearing block).
In other applications, the bushing must be installed within a “closed” gland that is spaced from the axial ends of a solid bore. In such cases, the bushing must be deflectable, at least to a certain extent, to enable the outside diameter of the body to inwardly deflect or contract for axial displacement of the body through the bore, and then expand outwardly when positioned within the gland. The bushings in such applications are typically formed of a polymeric material to enable such radial contraction and expansion. However, in high pressure applications, such polymeric bushings may lack the necessary material strength and thereby fail under loading.